Xerographic microfilm enlarger



Sept. 3, 1963 E. R. SABEL ETAL XEROGRAPHIC MICROFILM ENLARGER 2 Sheets-Sheet 1 Filed June 22, 1960 am U .B M m AF 0 TSF T N .U T E L A VDE mR M N m n E W; A 7 Y B Sept. 3, 1963 Filed June 22, 1960 E. R. SABEL ETAI. 3,102,449

XEROGRAPHIC MICROFILM ENLARGER 2 Sheets-Sheet 2 5 50 w W 2 I5 4 g I QL 8 my I L i g L w 5 INVENTOR.

2 EDWARD R. SABEL BY LIONEL E. LUFFMAN A T TORNE V United States Patent 8,182,449 XEROGRAPHIC MICROFILM ENLARGER Edward R. Sahel and Lionel E. Lufiman, Rochester, N.Y., assignors to Xerox Corporation, Rochester, N .Y.,

a corporation of New Yorlr Filed June 22, 1960, Ser. No. 37,984 7 Claims. (Cl. 88-44) This invention relates to 'xerography and particularly to improved apparatus for projecting a microfilm image at increased magnification onto an xerographic plate.

In the process of xerography, for example, as disclosed in Carlson Patent 2,297,691, issued October 6, 1942, a xerographic plate comprising a layer of photoconductive insulating material on a conductive backing is given a uniform electric charge over its surface and is then exposed to the subject matter to be reproduced, usually by conventional projection techniques. This exposure discharges the plate areas in accordance with the radiation intensity that reaches them, and thereby creates an electrostatic latent image on or in the photoconductive layer. Development of the latent image is effected with an electrostatically charged, finely divided material such as an electroscopic powder that is brought into surface contact with the photoconductive layer andis held thereon electrostatically in a pattern coresponding to the electrostatic latent image, Therefter, the developed xerographic powder image is usually transferred to a support surface to which it may be fixed by any suitable means.

Xerography has gained wide commercial success as a convenient and accurate method for the reproduction of copy, producing copy of high resolution. One of the virtues of xerography is its ability to reproduce copy onto a variety of support surfaces from most any original surface bearing image configurations capable of visual reproduction;

A variety of apparatuses for producing xerographic EJ084453 Patented Sept. 3, 19633 filled with appanatus of the present invention which is an copy from microfilm have been developed and marketed I typical of which is disclosed in copending application S.N. 796,561, filed March 2, 1959, in the name of S. R. Johanson, now U.S. Patent No. 3,049,968, issued Aug. 2, 1962. The apparatus therein disclosed is a form of automatic xerographic equipment that permits reproduction from continuously moving microfilm and offers a wide choice of magnification ratios at which the microfilm can be reproduced.

Another form of apparatus for reproducing from microfilm is disclosed in copending application Ser. No. 776,848, filed November 28, 1958, in the name of R. A. Hunt. In the latter copending application the apparatus thereof automatically and in seriatim reproduces from microfilm mounted on conventional record cards of the type widely used in record controlled accounting and tabulating systems. Typical microfilm cards of the type reproduced by the Hunt apparatus are disclosed in US. Patents 2,511,859; 2,512,106; and 2,598,022.

Both the Johanson and Hunt apparatuses have gained considerable favor among consumers having a substantially continuous need for reproducing from microfilm as would justifya relatively large expenditure for the relatively complex reproducing equipment. Typical users of this equipment are publishing houses or large manufacturing concerns as, for example, those which for convenience store volumes of engineering drawings on microfilm.

Whereas apparatuses of the type disclosed in the copending applications above-cited have proved successful commodities, their respective markets are limited to large concerns which financially can afford to own or lease the apparatus to reproduce microfilm but are financially improved microfilm enlarger that is simple, efficient, compact and relatively less expensive than apparatus available heretofore. Additionally, since the need to reproduce microfilm exists among present users of xerographic equipment, versatility of their present equipment is thereby enhanced with the apparatus of the invention.

The principal object of the invention is improved ap paratus to xerographically reproduce microfilm that is simple, efficient, compact and relatively less expensive than apparatus available heretofore.

p This and other objects of the invention are attained by means of the apparatus of the invention.

A preferred embodiment of the invention is shown in the accompanying drawings in which:

FIG. 1 is a perspective view of the apparatus of the invention shown as for reproducing from micro-film supplied on a reel;

FIG. 2 is a side elevation of the enclosure and bellows portion of the invention partially broken away to facilitate understanding of its construction; and

FIG. 3 is a continuation of FIG. 2 being a side elevation of the projection unit of the invention partially broken away to facilitate understanding of its construction.

As in all Xerographic systems based on the concept disclosed in the above cited Carlson patent, a xerographic plate having a photoconductive surface on a conductive backing is sensitized prior to exposure by means of a screened corona generating device which may be ofa type disclosed in Mayo Patent US. 2,778,946 that has been marketed with a developing apparatus of the type disclosed in Sabal et al. Patent US. 2,600,580. After sensitizing, the plate is usually removed in a light-tight cassette, which may be of a type disclosed in Mayo Patent U.S. 2,619,418, to an exposure apparatus which for opaque originals may be of the type disclosed in Mayo et al. Patent US. 2,781,704. The cassette is inserted into the exposure apparatus after which the cover of the cassette is removed. Exposure of a radiation light image of copy to be reproduced discharges the photoconductive plate layer in'the areas struck by radiation whereby there remains on the surface of the xerographic plate an electrostatic latent image in image configuration corresponding to the'image exposed. After exposure the cover is reinserted into the cassette and the plate removed to a developing apparatus, which may be of a type referred to in the above-cited Sabel patent, in which a two-component developing material, which may be of a type disclosed in Walkup Patent US. 2,638,416, is cascaded over the plate surface.

After developing, the powder image is electrostatically transferred to a suitable support surface which may be of any convenient type such as paper by means of the corona generating device mentioned above. After tnansfer the support surface is placed in :a suitable fusing device which may conveniently be a heat fuser of the type disclosed in Sahel et al. Patent 2,586,484 or a vapor fuser of the type disclosed in Carlson Patent US. 2,776,907 whereby the powder image is permanently *affixed to the support surface.

After transfer the plate surface is cleaned and the cycle may be repeated. It is to be noted that the above xerographic apparatuses for charging, developing, transfer and fusing have been extensively marketed and consumers having them can increasingly utilize them in connection with the microfilm exposure apparatus of the invention.

Referring more particularly to the drawings the apparatus of the invention is illustrated in FIG. 1 supported on a table surface at a height which is convenient for an operator to look down on the apparatus. As shown in FIG. 1 the apparatus is supported on base and includes a light-tight housing 1, an extensible bellows 2, and a projection unit generally designated as 3 which is slid able in a horizontal plane on track 4. v

For projecting a microfilm image the projection unit includes in operative relation (refer FIG. 3) an objective lens assembly generally designated as 17, a film support means generally designated as 18, a condenser lens 19 and a lamp assembly 20, all being supported on a pair of braces 21 and 22. The braces are joined by plate 23 which is supported for movement on track 4 so that the length of optical path. between film in its support means and a xerographic plate in its holder described below, may be varied in accordance with a selected magnification ratio at which the microfilm image is to be reproduced.

For selected positioning of the projection unit in accordance with magnification ratio, track 4 is indexed with guide marks and numbers 25'. The guide marks and numbers correspond to magnification ratios from 7.5 to diameters, whereby alignment of pointer 24 (FIG. 2) opposite a guide mark effects proper length of the optical path for a magnification ratio corresponding to the numerical index of the mark. Detent unit 28 having suitable clamping means (not shown) and operable by handle 29, secures plate 2 3 to track 4 in a selected position.

Film support means 18 is arranged to support microfilm which may be on a continuous web or in a microfilm card of the above mentioned type in projection relation to the other elements hereof. The film support means is secured to condenser barrel 3'2 and may be rotated therewith by means of handle 33. Stop pin 42, protruding into slot 63 which extends over a90" are, limits the angular rotation of the condenser in either direction. The film support means includes a film holder 34 in which film is inserted between parallel glass closure means 35 and 36 which secure the film in front of apertures therein (not shown) in the optical path. The film holder is removable from the apparatus and for each size film to be reproduced and/ or for microfilm cards a separate film holder may be provided. Generally, the film sizes most frequently used are 35 mm. and 16 mm. and it has been the practice to employ one size film holder for both sizes of film, permitting light to spill over the edges when using a 35 mm. holder for 16 mm. film. 'For placing film between the closures, adapter cam 37, arranged as a ring onthe barrel, has a knob 52 by which the cam can be partially rotated on the barrel such that wedge-flats 38 permit pin 39 :to be urged back by spring 40 to effect separation of closure 36 from 35 by the urgence of a pair of springs 41. After placing the film in the holder the adapter cam is rotated back securing the film between the closures.

When reproducing from microfilm cards, they are individually placed in a microfilm-card holder which is provided with suitable guides and stops for effecting proper alignment of the film relative to the apertures of the film support means. By using 'a non-positioning type of card holder, it is possible to enlarge a segment of the microfilm frame. This is done by scanning. the frame until the segment desired shows on the ground glass. This section is then aligned and the card locked in position.

For reproducing from microfilm wound on a reel, such as illustrated, the supply reel is secured on either of shafts 43 or 44 which are rotatably secured to film support arms 45 and 46 respectively, with the take-up reel being secured to theother shaft. Assuming the supply reel to be 4 on shaft 44, film is threaded around guide roll 47 through a film holder, as described .above, around guide roll 48 and onto the take-up reel. Suitable means are provided for aligning the film as desired in the optical path, and by means of :a handle 54- on both reels, the film can, be advanced or indexed to the desired frame. It is to be noted here, as will be understood by those having knowledge of optics, that the projected image will experience image reversals by the optics of the apparatus described below so that in placing the film in the support means it must be placed to result in an electrostatic latent image on a Xerographic plate reversed from the manner in which it is to appear on the support surface.

For illuminating an image on the microfilm the lamp assembly includes a conventional type projection lamp 49 suitably supported in the assembly and supplied from a suitable potential source through automatic timer control 50 (shown on FIG. 2) The timer control includes a presettable time controller 5-3 and may be a standard commercially available type. The timer includes a single pole double throw switch that controls the light value. One

pole provides full line voltage to the lamp for focusing and the other pole shunts the line througha resistor in the timed circuit for exposure. lamp is concentrated by the condenser lens 1 9 having lens elements 5 1.

Projection of a radiation image is elfected by the objective lens assembly 17 which includes an outer light-tight sleeve 55 suitably supported between the filmsuppor-t means and hub 56 extending from brace 21. Within the sleeve, objective lens 57 is secured in lens barrel '58 and in preferred embodiment the lens has 'a focal length of 65' millimeters. Lever 59 is secured to the lens barrel through helixical slot 61 of the sleeve and for focusing the lens the lever is moved up or down in the slot. For convenience of gripping the lever, a knob 61 is secured thereon and an expansion spring 62 between the knob and the sleeve sustains the focused position.

The lens projects the image through extensible bellows 2 (FIG. 2) which is secured to envelop the openings (not shown) of brace 21 and housing 1. The image projected through the bellows strikes the reflecting surface of mirror 69, suitably supported within housing 1 at an angle which may be 45 degrees, and from the mirror the image is reflected upwards to either a xerographic plate 14 or ground glass 12 whichever is in place thereon as described below.

For supporting a xerographic plate in the apparatus,

housing 1 includes a plate holder generally designated as 10. The holder has a frame 11 secured in light-tight relation to the housing and is adapted to support a ground be exposed to the interior of the housing by removing the cassette cover. Without the xerographic plate. in place, an image projected by the projection unit can be viewed on the ground glass before inserting the plate.

By means of theright angle projection path,the overall length of the unit is reduced and the. focal plane is at a convenient height and position for ground glass reading. With this arrangement and for up to- 15 diameter magnification, a unit'can be fabricated having approximate dimensions of 48 inches long, 18 inches wide and 21 inches high.

In operation, microfilm on either a microfilm card, continuous strip or the like having an image to be reproduced is placed in the film support means having a film holder appropriate for the size film to be reproduced. Projection unit 2 is then moved on track 4 until pointer 24 aligns opposite an index guide mark 25 of a magnification ratio to be selected at which the image is to bereproduced. Through toggle switch 74 on timer 5i lamp 4-9-ls illumi- The illumination of the ground glass appears in sharp outline;

rotating the optical system and the film support means by use of connecting handle 33. This allows for orienting an image either horizontally or vertically on the xerographic plate or any orientation therebetween.

The apparatus is then ready for exposure of the microfilm image to a xerographic plate; The lamp is turned off and a xerographic plate is sensitized by a corona gem erating device as described above. The sensitized plate is carried in a cassette and placed in plate holder lo below the ground-glass after which the cassette cover plate is removed to expose the sensitized plate surface to the interior of housing 1. Energizing the timer through a push button 75 effects a time controlled radiation image exposure of the microfilm to the Xerographicplate. After exposure, the cover plate is reinserted into the cassette and the xerographic plate removedto, apparatus for developing the electrostatic latent image thus formed. The devev-loped image is thereafter transferred and perina- "nentlyaffixed to a suitable support surface. I

By the apparatus thus described there is disclosed an improved microfilm enlarger for projecting microfilm images at increased magnification ratio onto a xerographic plate by means of an apparatus that is compact, efiicient and relatively less expensive than apparatus available heretofore.

Since many changes could be made in the above c0nstruction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. Apparatus to project microfilm at an increasedrnagnification ratio onto a previously removedly charged flat xerographic plate, including in combination a projection system, said projection system including in operative relation lamp means adapted to be connected to a potential source, a condenser lens, film support means closely spaced and integrally coupled to said condenser lens and arrangedto support microfilm to be reproduced in a projection plane, said film support means including a film holding member removably interchangeable therein" for ,holdin-g'film of different sizes or mounts, parallel spaced closure means operable to slideably receive said film holding means therebetween and secure the film thereat in the projection plane, and means to operate said closure means to eiiect separation and closure thereof whereby to re- I ceive and secure respectively a film holder containing film to be reproduced, and an adjustable objective lens capable of being foocused to film in the film support means; a boxlike enclosure having xerographic plate holding means arranged to receive and support a previously removedly charged flat Xerographic plate in a horizontal plane and 15 diameters, including in combination horizontalsupport means, a projection system adapted for movement on said support means, said projection system including in operative relation lamp means adapted to be connected to a potential source, a condenser lens, film support means closely spaced and integrally coupled to said condenser lens and arranged tosupport microfilm to be reproduced in a projection plane, said film support means including a film holding member removably interchangeable therein for holding film of different sizes or mounts, parallel spaced closure means operable to slideably receive said film holding means therebetween and secure the film thereat in the projection plane, and means to operate said closure means to effect separation and closure thereof whereby to receive and secure respectively a film holder containing film to be reproduced, and an adjustable o'bjective lens capable of being focused to film in the film support means; a box-like enclosure having xerographic plate holding means arranged to receive and support a previously removedly charged flat xerographic plate in a horizontal plane and in light-tight relation to the interior of said enclosure, an extensible bellows secured between the enclosure and said projection system to provide an extensible light-tight enclosure therebetween, a reflective surface member secured within said enclosure and arranged to reflect an image projected from said projection system normally onto a xerographic plate in the plate holding means, an index on said support means correlated to projection distances for the range of said magnification ratios, and means to position said projection system on the support means relative to said index.

3. Apparatus to project microfilm at an increased magnification ratio onto a previously removedly charged flat xerographic plate, including in combination a projection secure the film thereat in the projection plane, and means to operate saidclosure means to efifect separation and closure thereof whereby to receive and secure respectively a film holder containing film to be reproduced, and an adjustable objective lens capable of being focused to film in the film support means; a box-like enclosure having means selectively to support a ground-glass in a horizontal plane for viewing a projected image to be reproduced or to receive and support a previously removedly charged fiat xerographic plate in the plane of said glass and in lighttight relation to the interior of said enclosure, said last recited means including yieldable detent means urging said ground glass into said viewing position and displacable for supporting a Xerographic plate between the ground glass and said enclosure, an extensible bellows secured between the enclosure and said projection system to provide an extensible light-tight enclosure therebetween, a mirror secured within said enclosure having its mirrored surface arranged to reflect an image projected from said projection system normally onto a Xerograp'hic plate in the plate holding means, and means to position said projection system at a distance from said enclosure correlated to the ratio at which magnification is to be eflected.

.4. Apparatus to project microfilm at increased magnification ratio onto a previously removedly charged fiat xerographic plate, including in combination a projection system adapted for sliding movement in a horizontal plane, said projection system including in operative relation lamp means adapted to be connected to a potential source, a

condenser lens, film support means closely spaced and integrally coupled to said condenser lens and adapted to' support microfilm to be reproduced vertically in a projection plane, said film support means including a film holding member removably interchangeable therein for holding film of different sizes or mounts, parallel spaced closure means operable to slideably receive said film holding means therebetween and secure the film thereat in the projection plane, means to operate said closure means to plate holding means arranged to receive and support a previously externally charged flat xerographic plate in a horizontal plane and in light-tight relation to the interior of said enclosure, an extensible bellows secured between the enclosure and said projection system to provide, an extensible light-tight enclosure therebetween, and a mirror secured within said enclosure having its mirrored surface arranged to reflect an image'projected from said projection system normally on to a xero graphic plate in the plate holding means.

5. Apparatus to project microfilm at increased magnification ratio onto a previouslyremovedly charged fiat xerographic plate, including in combination a projection system adapted for movement in a horizontal plane, said projection system including in operative relation lamp means adapted to be connected to a potential source, a

condenser lens, film support means closely spaced and integrally-coupled to said condenser lens and which interchangeably accommodates microfilm Webor microfilm cards with images to be reproduced and arranged to support microfilm of either type interchangeably in a projection plane, said film support means including a film holding member removably interchangeable therein for holding either web or car-d mounted film of different sizes, parallel spaced closure means operable to slideably receive said-film holding means therebetween and secure the film thereat in the projection planeQand means to perate said closure means to effect separation' andclosure thereof whereby to receive and secure respectively a film holder containing film to be reproduced, and an adjustable objective lens capable of being focused to film in the film support means; a box-like enclosure having xerographic plate holding means arranged to receive and sup- 2 port a previously removedly charged flat xerogralphic plate in a horizontal plane and in light-tight relation to the, interior of said enclosure, an extensible bellows secured between the enclosure and said projection system to provide an extensible light-tight enclosure therebetween, and a reflective surface member secured within said enclosure and :arranged to reflect an image projected from said projection system normally onto a xerograrphic plate in the plate holding means.

6. Apparatus to project microfilm at an increased magnification ratio onto a previously removedly charged flat xerographic plate, including in combination a projection system, said projection system including in operative rela tion lamp means adapted to be connected to a potential source, a condenser lens, fi-lm support means closely spaced and integrally coupled to said condenser lens and arranged to support microfilm to be reproduced in a projection plane, said film support means including a film holding member removably interchangeable therein for holding film of different sizes or mounts, parallel spaced closure means operable to slideably receive said film holding means therebetween and secure the film thereat in the projection plane, and means to operate said closure means to eifect separation and closure thereof whereby to receive and secure respectively a film holder containing film to be reproduced, and an'adjustable objective lens capable of being focused to film in the film support means; a box-like enclosure having xerographic plate holding means arranged to receive and support a previously removed charged fiat xenographic plate in a plane angularly displaced from the plane of film in its support means and in light-tight relation to the interior of said enclosure, an extensible bellows secured between the enclosure and said projection system to provide an extensrble light tight enclosure therebetween, and a reflective surface member secured Within said enclosure and arranged to reflect an image projected from said projection system normally onto a xenographic plate in the plate holding means.

7. Apparatus according to claim 6 in which the angular displacement of the plane of the xerograpl'lic plate in the plate holding means is substantially from the I plane of film in its support means.

References Cited in the file of this patent UNITED STATES PATENTS 1,157,611 Beidler -1 Oct. 19, 1915 1,970,593 Bigelow Aug. 21, 1934 2,229,761 Mueller Ian. 28, 1941 12,357,809 Carlson Sept. 12,1944 2,758,524 Sugarman Aug. 14, 1956 2,771,002 Mayo et a1. Nov. 20, 1956 2,781,704 Mayo et al. Feb. 19,. 1957 2,816,493 Lewis et al. Dec. 17, 1957 2,817,277 Bogdonoif Dec. 24, 1957 2,940,358 Rosenthal June 14, 1960 3,011,963 Johnson et a1. Dec. 5, 1961 3,028,799 Keller let a1. Apr. 10, 1962 

1. APPARATUS TO PROJECT MICROFILM AT AN INCREASED MAGNIFICATION RATIO ONTO A PREVIOUSLY REMOVEDLY CHARGED FLAT XEROGRAPHIC PLATE, INCLUDING IN COMBINATION A PROJECTION SYSTEM, SAID PROJECTION SYSTEM INCLUDING IN OPERATIVE RELATION LAMP MEANS ADAPTED TO BE CONNECTED TO A POTENTIAL SOURCE, A CONDENSER LENS, FILM SUPPORT MEANS CLOSELY SPACED AND INTEGRALLY COUPLED TO SAID CONDENSER LENS AND ARRANGED TO SUPPORT MICROFILM TO BE REPRODUCED IN A PROJECTION PLANE, SAID FILM SUPPORT MEANS INCLUDING A FILM HOLDING MEMBER REMOVABLY INTERCHANGEABLE THEREIN FOR HOLDING FILM OF DIFFERENT SIZES OR MOUNTS, PARALLEL SPACED CLOSURE MEANS OPERABLE TO SLIDEABLY RECEIVE SAID FILM HOLDING MEANS THEREBETWEEN AND SECURE THE FILM THEREAT IN THE PROJECTION PLANE, AND MEANS TO OPERATE SAID CLOSURE MEANS TO EFFECT SEPARATION AND CLOSURE THEREOF WHEREBY TO RECEIVE AND SECURE RESPECTIVELY A FILM HOLDER CONTAINING FILM TO BE REPRODUCED, AND AN ADJUSTABLE OBJECTIVE LENS CAPABLE OF BEING FOCUSED TO FILM IN THE FILM SUPPORT MEANS; A BOXLIKE ENCLOSURE HAVING XEROGRAPHIC PLATE HOLDING MEANS ARRANGED TO RECEIVE AND SUPPORT A PREVIOUSLY REMOVEDLY CHARGED FLAT XEROGRAPHIC PLATE IN A HORIZONTAL PLANE AND IN LIGHT-TIGHT RELATION TO THE INTERIOR OF SAID ENCLOSURE, AN EXTENSIBLE BELLOWS SECURED BETWEEN THE ENCLOSURE AND SAID PROJECTION SYSTEM TO PROVIDE AN EXTENSIBLE LIGHT-TIGHT ENCLOSURE THEREBETWEEN, AND A REFLECTIVE SURFACE MEMBER SECURED WITHIN SAID ENCLOSURE AND ARRANGED TO REFLECT AN IMAGE PROJECTED FROM SAID PROJECTION SYSTEM NORMALLY ONTO A XEROGRAPHIC PLATE IN THE PLATE HOLDING MEANS. 